The major blow to the Delhi Police comes after the High Court had repeatedly rebuked the former over the exceedingly slow progress in the matter, which was peppered with several loopholes.

Earlier on May 3, a sessions court quashed a lower court order that directed nine JNU students to appear before it to record their consent or refusal for a lie-detector test in connection with a case of missing university student Najeeb.

Additional Sessions Judge Siddharth Sharma dismissed a magisterial court's order dated March 30 and rejected the notice of Delhi Police.

The Sessions court also granted liberty to issue fresh notice related to lie detector test of the students as per guidelines.

Patiala House Court Chief Metropolitan Magistrate Sumit Dass had earlier asked the students to appear before the court.

The Delhi Police had issued a notice to the students and asked them to appear before it for a lie-detector test.

After receiving the summons, the students had opposed the police's move.

Earlier in February, the Delhi Police was pulled up by the Delhi High Court over their slow progress in the case and was asked to explore other prospects of the probe like polygraph test of other persons connected with the disappearance of Ahmed as all other leads in this case have not yielded any good result.

"The student had gone missing in October 2016; it is February now. Nearly four months have gone by and none of the leads are going anywhere. We asked for a polygraph test as the other leads have not yielded any results," the court observed.

The High Court was hearing an application by one of the nine students, who are suspects in the case, seeking a recall of the High Court's order dated December 14 and December 22, 2016.

The application had alleged that by means of these two orders, the court was regulating the manner of investigation, which was prejudicing the probe and violating their rights under Articles 21 and 22 of the Constitution.

The applicant had also challenged a notice issued to him by the Delhi Police to appear before the trial court to give consent for a lie-detector test.

The Delhi Government's counsel opposed the application, stating that the same student had moved a similar plea through another lawyer earlier and the High Court on January 23 disposed of it by asking the student to come forward.

A habeas corpus plea was moved by Najeeb's mother, Fatima Nafees, who sought direction to trace her son who has been missing since the intervening night of October 14-15.

Najeeb, 27, a first-year M.Sc. student, went missing from his JNU hostel, allegedly after a row with members of RSS student wing Akhil Bharatiya Vidyarthi Parishad (ABVP).